docs: def timeline_slider(self, text='Time', ax=None, valfmt=None, color=None):
          """Creates a timeline slider.
  
          Parameters
          ----------
          text : str, optional
              The text to display for the slider. Defaults to 'Time'
          ax : matplotlib.axes.Axes, optional
              The matplotlib axes to attach the slider to.
          valfmt : str, optional
              a format specifier used to print the time
              Defaults to '%s' for datetime64, timedelta64 and '%1.2f' otherwise.
          color :
              The color of the slider.
          """
          if ax is None:
              adjust_plot = {'bottom': .2}
              rect = [.18, .05, .5, .03]
  
              plt.subplots_adjust(**adjust_plot)
              self.slider_ax = plt.axes(rect)
          else:
              self.slider_ax = ax
  
          if valfmt is None:
              if (np.issubdtype(self.timeline.t.dtype, np.datetime64)
                 or np.issubdtype(self.timeline.t.dtype, np.timedelta64)):
                  valfmt = '%s'
              else:
                  valfmt = '%1.2f'
  
          if self.timeline.log:
              valfmt = '$10^{%s}$' % valfmt
  
          self.slider = Slider(
              self.slider_ax, text, 0, self.timeline._len-1,
              valinit=0,
              valfmt=(valfmt+self.timeline.units),
              valstep=1, color=color
          )
          self._has_slider = True
  
          def set_time(t):
              self.timeline.index = int(self.slider.val)
              self.slider.valtext.set_text(
                  self.slider.valfmt % (self.timeline[self.timeline.index]))
              if self._pause:
                  for block in self.blocks:
                      block._update(self.timeline.index)
                  self.fig.canvas.draw()
          self.slider.on_changed(set_time)